In Situ Monitoring of Pitting Corrosion on Stainless Steel with Digital Holographic Surface Imaging

Abstract

© The Author(s) 2019 A new approach - the digital holographic surface imaging (DHSI) - is proposed for in situ observation of the electrode surface during a typical localized corrosion process. The test results show that the experimental system is sensitive in detecting ions' concentration changes in the vicinity of the electrode surface. The phase maps obtained with this method capture the dynamic concentration changes in front of the steel surface and exhibit the initiation, propagation or re-passivation processes of metastable pits. The proposed method can provide visual evidence of localized dissolution on the electrode surface and offer an in situ and simple means to monitor early-stage corrosion in real time, thereby exhibiting potential for extensive use in the study of electrochemical dynamic processes.